CN101118275A - On-line Monitoring Method of Opening and Closing Time of High Voltage Circuit Breaker - Google Patents

Abstract

The online monitoring method of opening and closing time of a high-voltage circuit breaker is to obtain the initial moment when the opening and closing coils of a circuit breaker are electrified by performing voltage remote signal sampling on the opening and closing coils of a circuit breaker. The capacitive sensor conducts three-phase voltage remote signal sampling to obtain the moment when the circuit breaker contacts are separated and joined, and calculates the time difference between the initial moment when the circuit breaker opening coil is electrified and the moment when the circuit breaker contacts are separated, and the circuit breaker is obtained. Opening time, calculate the time difference between the start time of the charging of the circuit breaker closing coil and the time when the circuit breaker contact is completed, that is, the closing time of the circuit breaker. The method of the invention is based on voltage signal remote signal sampling, fully utilizes the operating facilities of the power system, overcomes the disadvantages of the previous online monitoring method, makes the determination of the time point more convenient, accurate, and low in cost, and is conducive to realizing the "conditional maintenance" of the circuit breaker.

Description

On-line Monitoring Method of Opening and Closing Time of High Voltage Circuit Breaker

technical field

The invention relates to an on-line monitoring method for a high-voltage circuit breaker, in particular to an on-line monitoring method for the opening and closing time of a high-voltage circuit breaker.

Background technique

Among the devices in the power system, the high-voltage circuit breakers have the largest number, a large amount of maintenance, and high costs. Relevant statistics show that more than half of substation maintenance costs are spent on high-voltage circuit breakers, and 60% of them are used for minor repairs and routine maintenance of circuit breakers. In the past, planned maintenance based on cycle (time) was carried out. According to statistics, 10% of circuit breaker failures are caused by incorrect maintenance. The circuit breaker must be completely disassembled during the overhaul, which is time-consuming and expensive. Disassembly and reassembly can introduce many new defects. In order to improve the pertinence of maintenance, it is necessary to implement on-line status monitoring of high-voltage circuit breakers, so that planned maintenance can be transformed into condition-based maintenance, and maintenance decisions can be made based on online monitoring data.

The opening/closing time of the high-voltage circuit breaker is an important content of the on-line monitoring of the circuit breaker, and it is also an important index to measure the state of the circuit breaker. The relevant parameters are defined as follows:

Closing time: the time from the moment the closing command is received to the moment when all pole contacts are in contact.

Opening time: the time from the moment when the opening command is received to the moment when all pole contacts are separated.

Unsynchronized closing: the time from when the first pole contact is closed to when all pole contacts are closed.

Different period of opening: the time from the opening of the first pole contact to the opening of all pole contacts.

According to the definition, the opening/closing time of the circuit breaker is the time difference between the starting moment of the opening/closing circuit of the circuit breaker and the moment when the contact opening/closing of the circuit breaker is completed, and the accuracy of the time is required to be 1 millisecond. The whole process involves the determination of two moments. The first is the initial moment when the circuit breaker opening/closing circuit is electrified; the second is the moment when the circuit breaker contacts are opened/closed.

For the first question, the current practice is that the Hall sensor is generally used in the online monitoring device to sample the current of the coil in the opening/closing circuit of the circuit breaker, and use it as the criterion for the electrification of the opening/closing circuit. When the brake coil is electrified, the opening/closing process of the circuit breaker begins. In the monitoring of the current, a current threshold value must be set. When the current of the opening/closing coil is greater than the threshold value, it is considered that the opening/closing process of the circuit breaker has started, and the moment at this point is regarded as the opening/closing process of the circuit breaker. The moment when closing starts. This method has the following disadvantages: 1: The current of the opening/closing coil of the circuit breaker itself is an object of on-line monitoring of the circuit breaker, and the magnitude and duration of the opening/closing coil current reflect the mechanical operation of the circuit breaker The quality of the mechanism reflects the advantages and disadvantages of the mechanical characteristics of the circuit breaker. Once the performance of the operating mechanism is poor, it will directly affect the current of the opening/closing coil of the circuit breaker; 2: The resistance of the opening/closing coil of different circuit breakers It is different from reactance, and the current of the corresponding opening/closing coil will also be different; 3: Different R-L parameters of different coils affect the steepness of current rise, and it is difficult to set the threshold or threshold value of "current or no current" 4: The opening/closing coil current of the circuit breaker has a changing process, and different threshold values will correspond to different time points. Therefore, different threshold value settings will produce Different starting moments of the closing process; 5: The fault of the circuit breaker (including the fault of the operating mechanism) will cause the change of the coil current.

For the second problem, different existing on-line monitoring devices adopt different methods.

1) External current transformers are usually used, and the moment when the last phase current of the main circuit of the circuit breaker is present or not is taken as the moment when the contact opening/closing of the circuit breaker is completed. In fact, when closing, when the moving contact of the circuit breaker has not reached the closing position point, the main circuit has already passed the pre-breakdown current, so the presence or absence of current cannot correctly reflect the actual closing of the contact of the circuit breaker time. This method also has the following defects: first, there must be a load current, once there is no load in the operation process, the existence of the current cannot be monitored, and the location cannot be located; second, the threshold value for judging the existence of the current The size affects the accuracy of the opening/closing completion time of the circuit breaker contacts; thirdly, a current transformer must be installed in the online monitoring device. If it is used together with the current transformer existing in the original system, the damage of the monitoring device is likely to affect the use The performance of other devices of the current transformer is contrary to the principle that the added monitoring device cannot destroy the performance of the original device.

2) Some vibration sensors are added to determine the moment when the circuit breaker contacts are opened/closed based on mechanical vibration signals.

Acceleration sensors are generally used to collect vibration signals. The acceleration sensor converts the contact vibration signal into a charge signal, converts it into a voltage signal through a charge amplifier, and then obtains a fault signal through a resonance demodulator. However, the analysis of the vibration signal of the circuit breaker contact is a difficult point in the monitoring of mechanical characteristics: 1. Due to the complex structure of the circuit breaker and the influence of various environmental noises during on-site measurement, the vibration signal obtained by the acceleration sensor has interference components; 2. Open circuit The close operation or separation operation of the device will generate several vibration events. The actual vibration signal and the dispersion, reflection and refraction of the vibration signal make the identification more difficult. If the vibration signal is small, it will be more difficult to identify; 3. When the instantaneous When the amplitude and frequency are large enough to be comparable to vibration signals, it is difficult to effectively distinguish noise from useful signals using traditional methods. At present, time-domain method, frequency-domain method and joint time-frequency analysis method are used to analyze the vibration signal of circuit breaker contacts. Among them, the time-domain method is intuitive and simple, and is the preferred method for vibration signal analysis. The frequency domain method and the time-frequency joint analysis method are complex and have a large amount of calculation, and are generally used in the upper-level fault diagnosis software. Document 1 (Meng Yongpeng et al. Application of short-time energy method in state monitoring of circuit breaker mechanical characteristics. Journal of Xi'an Jiaotong University, December 2004) proposed a time-domain analysis method for short-time energy, which can significantly improve the signal-to-noise ratio. With strong noise suppression ability, it is used for event time extraction of circuit breaker vibration signal. By selecting the appropriate sensor measurement position, the state parameters such as the closing synchronism and closing time of the circuit breaker can be accurately obtained, which provides a corresponding quantitative basis for the detection of the mechanical state of the circuit breaker. The disadvantage of this method is that multiple acceleration sensors need to be placed in different positions. Frequency domain analysis method, conventional spectrum analysis is realized by discrete Fourier transform (DFT) or fast Fourier transform (FFT). Because FFT is difficult to effectively improve the spectrum resolution, literature 2 (Zhao Xia, Xiong Xiaofu, Guo Ke, etc. Analysis of vibration signals of circuit breaker operating mechanism with refined spectrum technology [J]. Electric Power System Automation, 2003, 27(12) : 37-40, 80.) proposed to use the refined spectrum analysis method to analyze the frequency domain characteristics and frequency structure of the vibration signal of the circuit breaker operating mechanism. Its disadvantage is that the reflected time signal is not enough. At present, signal analysis and processing methods such as neural network and wavelet analysis are also widely used in the identification of vibration signals, and more circuit breaker status signals can be obtained from mechanical vibration signals, but many of these processing technologies are still limited to experiments, researching.

The way of analyzing the mechanical vibration signal is theoretically considered, it should be a simple and effective method to judge the state of the circuit breaker by installing a vibration sensor to collect the vibration signal to judge the state of the circuit breaker. But in practical application, there are the following disadvantages: First, the installation of the vibration sensor is a big problem. There is no unified statement on the number of applications and the determination of the installation location of the vibration sensor; secondly, the vibration signal contains a lot of interference signals, which is very critical to the processing method of the vibration signal of the circuit breaker, and these are still being explored and studied. Therefore, there are not many people who actually apply this method in practice.

3) Use the state signal of the auxiliary switch contact to determine the moment when the circuit breaker contacts are opened/closed. Since the auxiliary switch is a mechanical contact switch, the conversion speed is poor and unstable, so the measurement results are biased; what's more, the auxiliary contact of the circuit breaker is also one of the parameters of the circuit breaker's online monitoring.

In short, the existing on-line detection methods for the opening and closing time of high-voltage circuit breakers all have their own shortcomings, such as high practical application cost, poor accuracy and unsatisfactory effect.

At present, the high-voltage live display device installed on the switchgear together with the high-voltage circuit breaker has become an indispensable electrical equipment in the power system. It consists of two parts: a high-voltage insulator with a capacitive sensor and a high-voltage live display. Each phase (A, B, C phase) has a high-voltage insulator with a capacitive sensor. The high-voltage live display is directly connected to the capacitive sensor to monitor the voltage of the capacitive sensor. When the power line is charged, the capacitive sensor can be coupled through the electric field. The voltage is induced, and the presence or absence of the voltage signal is displayed through the charged display. When the circuit breaker performs remote opening/closing through the external opening/closing contacts, the circuit breaker performs the opening/closing of the contacts, and the live display on the line can display the opening/closing results of the line.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art, to provide a simple and accurate online monitoring method of the opening and closing time of the high-voltage circuit breaker, and to effectively perform the online monitoring of the opening and closing time of the circuit breaker. monitor.

The technical solution adopted by the present invention to solve the technical problems is as follows: an online monitoring method for the opening and closing time of a high-voltage circuit breaker, the on-line monitoring device monitors the opening time T0, closing time T1, and opening time Ttq0 of different phases of the circuit breaker , Closing different time Ttq1 for online monitoring, which includes the following steps:

(1) Sampling the remote signal of the voltage signal for the opening coil and closing coil of the circuit breaker, and recording the remote signal from scratch (from 0 to 1: 0--represents no voltage, 1--represents presence, There is voltage), which is the time Tf and Th when the voltage signal is established in the opening coil and closing coil, and Tf and Th are used as the starting time when the opening coil and closing coil of the circuit breaker are charged ;

(2), first convert the three-phase AC voltage of the capacitive sensor of the high-voltage live display device on the power line into a three-phase DC voltage, and then perform remote signaling sampling of the three-phase voltage signal, and record the three-phase remote signaling from presence to non-existence (from 1 The moment of displacement from 0 to 0) and from nothing to existence (from 0 to 1), the moment when the three-phase remote signal changes from existence to non-existence is the disappearance time of the three-phase voltage signal Taf, Tbf, Tcf, The moment when the three-phase remote signal changes from scratch is the establishment time Tah, Tbh, Tch of the three-phase voltage signal, and the disappearance time max(Taf, Tbf, Tcf) of the last phase voltage signal is used as the contact separation of the circuit breaker At the moment of completion, the establishment moment max(Tah, Tbh, Tch) of the last phase voltage signal is taken as the moment when the contacts of the circuit breaker are engaged;

(3) Calculate the time difference between the start time Tf of the charging circuit breaker opening circuit and the time max(Taf, Tbf, Tcf) when the circuit breaker contacts are separated, that is, the opening time T0 of the circuit breaker: T0=max(Taf , Tbf, Tcf)-Tf; Calculate the time difference between the start time Th of the circuit breaker closing circuit charging and the time max(Tah, Tbh, Tch) of the circuit breaker contact completion time, that is, the closing time T1 of the circuit breaker: T1=max(Tah, Tbh, Tch)-Th;

(4), calculate the maximum time difference of the three-phase voltage signal disappearance time Taf, Tbf, Tcf of the capacitive sensor, promptly obtain the different time Ttq0 of opening the gate of the circuit breaker: Ttq0=max(Taf, Tbf, Tcf)-min(Taf, Tbf, Tcf); Calculate the maximum time difference of the three-phase voltage signal establishment time Tah, Tbh, Tch of the capacitive sensor, that is, the different closing time Ttq1 of the circuit breaker: Ttq1=max(Tah, Tbh, Tch)-min(Tah , Tbh, Tch).

The beneficial effects of the present invention are as follows:

1. Through the analysis of the operating characteristics of the high-voltage circuit breaker, it is noted that the DC control power supply in the power system has a stable voltage (the range of the DC control power supply specified in the power system is 85% to 115% of the rated voltage, and the rated voltage is DC 220V That is to say, the voltage from the manufacturer of the DC control power supply must be controlled at 187V ~ 253V. Under normal circumstances, this voltage is required to be maintained at about 220V), so as to make full use of the stable voltage provided to the opening/closing coil of the circuit breaker. Advantageous conditions, through the remote signal sampling of the circuit breaker opening/closing coil voltage signal, the initial moment of charging of the circuit breaker opening/closing circuit can be obtained, which overcomes the various disadvantages brought about by sampling based on the current signal in the past, so that The determination of the time point is more reliable and accurate, and the accuracy requirements are consistent (accuracy requirements are determined by the sampling frequency of the voltage signal). On the basis of not adding any cost, the accurate determination of the charging time of the high-voltage circuit breaker opening/closing circuit is realized.

2. Make full use of the high-voltage live display device installed on the switchgear together with the high-voltage circuit breaker on the existing power line, and obtain the contact opening/closing of the circuit breaker by performing remote signal sampling of the three-phase voltage signal on the capacitive sensor of the high-voltage live display device At the end of the time, it overcomes the disadvantages of several different methods for measuring the opening/closing time of the circuit breaker contacts in the past, and makes the determination of the contact opening/closing time very simple, convenient, accurate and has the same accuracy requirements (accuracy requirements are determined by voltage The signal sampling frequency is determined), without increasing any device cost and without complex mathematical calculations, the determination of the opening/closing completion time of the contacts of the circuit breaker is realized.

3. The method of the present invention is based on voltage signal remote signal sampling, fully utilizes the operating facilities of the power system, makes the on-line monitoring technology of the circuit breaker more accurate, more convenient, and lower in cost, and lays the foundation for the "condition maintenance" of the circuit breaker, which can It can better save the maintenance cost of the power system and provide technical support for the safe operation of the power system.

Description of drawings

Fig. 1 is the flowchart of the method of the present invention.

Fig. 2 is a circuit block diagram related to the embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and examples. However, the invention is not limited to the examples given.

As shown in Figure 1, in the embodiment of the online monitoring method of the opening and closing time of the high-voltage circuit breaker of the present invention, the timer of the online monitoring device CPU triggers the three-phase capacitance sensor of the opening/closing coil of the circuit breaker and the high-voltage charged display device Carry out voltage signal remote signal sampling, the sampling frequency is 10000Hz, so that the monitoring time accuracy is 0.1 millisecond:

Determination of 1 minute/closing coil electrification time

Sampling the voltage remote signal of the opening coil and closing coil of the circuit breaker, and recording the remote signal displacement time of the opening/closing circuit during the opening/closing operation, that is, the voltage establishment of the opening coil and closing coil Time Tf, Th, and take Tf, Th as the initial moment of electrification of the opening coil and closing coil of the circuit breaker.

2 Determination of opening/closing time of circuit breaker contacts

Sampling the voltage remote signal of the three-phase capacitive sensor of the high-voltage live display device on the power line, and recording the displacement moment of the voltage remote signal of the three-phase capacitive sensor, that is, the disappearance time Taf, Tbf, Tcf of the voltage signal of the three-phase capacitive sensor during the opening operation And the establishment time Tah, Tbh, Tch of the voltage signal of the three-phase capacitance sensor during the closing operation, and the disappearance time max (Taf, Tbf, Tcf) of the voltage signal of the last phase capacitance sensor is taken as the time when the contact is separated during the opening operation of the circuit breaker ; The last phase capacitive sensor voltage signal establishment time max(Tah, Tbh, Tch) is used as the moment when the contactors are engaged during the closing operation of the circuit breaker.

3 Determination of circuit breaker opening/closing time and different time

Calculate the time difference between the start time Tf of the circuit breaker opening circuit electrification and the time max(Taf, Tbf, Tcf) when the circuit breaker contacts are separated, that is, the opening time T0 of the circuit breaker: T0=max(Taf, Tbf, Tcf )-Tf; Calculate the time difference between the start time Th of the charging circuit breaker closing circuit and the time max(Tah, Tbh, Tch) of the circuit breaker contact completion time, that is, the closing time T1 of the circuit breaker: T1=max( Tah, Tbh, Tch)-Th;

Calculate the maximum time difference between Taf, Tbf, and Tcf when the three-phase voltage signal of the capacitive sensor disappears, that is, the time Ttq0 of different phases of opening of the circuit breaker: Ttq0=max(Taf, Tbf, Tcf)-min(Taf, Tbf, Tcf) ;Calculate the maximum time difference of the three-phase voltage signal establishment time Tah, Tbh, Tch of the capacitive sensor, that is, the different closing time Ttq1 of the circuit breaker: Ttq1=max(Tah, Tbh, Tch)-min(Tah, Tbh, Tch ).

As shown in Figure 2, in the embodiment, when the external opening/closing operation is performed on the circuit breaker, first the opening/closing contact of the external remote control relay is used to transmit power to the opening/closing coil of the circuit breaker, when the coil current When it rises to a certain value, the magnet that pushes the coil moves to release the pre-stored torsion spring, rotate the main shaft, drive the contact of the circuit breaker to move, and realize the opening/closing function. Coil receiving power is the beginning of the whole process. Considering that the DC control power supply in the power system has a stable voltage, it is a stabilized voltage source. By monitoring the voltage of the opening/closing coil of the circuit breaker, it is possible to effectively know when To operate the circuit breaker, the moment the coil receives power is used as the starting moment for calculating the opening/closing time of the circuit breaker. The method of judging the coil receiving power is realized through external remote signaling:

In the embodiment, as shown in Figure 2, the positive power receiving end of the circuit breaker opening/closing coil is respectively connected to the remote signal input end of the online monitoring device, and the 220V- end of the external DC control power supply is connected to the on-line The negative terminal of the remote signal of the monitoring device; when there is no remote control opening/closing operation, the remote signal monitored by the online monitoring device is 0, when the external remote control performs the opening/closing operation of the circuit breaker, the external opening/closing trigger Point conduction, the external DC control power directly acts on the opening/closing coil, as long as the voltage of the DC control power is greater than 187 volts, the on-line monitoring device detects the remote signaling signal within 0.1 milliseconds (10000Hz sampling frequency) (1 ), record the moment of remote signaling displacement (from 0 to 1); in order to prevent the external power system magnetic field signal from interfering with the online monitoring device, causing wrong remote signaling displacement, a conventional software debounce is set for the remote signaling signal deal with. In this way, when the circuit breaker performs the opening operation, the voltage remote signal displacement time of the opening coil is obtained, that is, the electrification time Tf of the circuit breaker opening circuit; when the circuit breaker performs the closing operation, the closing coil The moment of voltage remote signal displacement, that is, the charging moment Th of the circuit breaker opening circuit.

In the embodiment, combined with the actual application of the power system, the high-voltage live display device has become an indispensable electrical equipment in the power system, and the three phases (A, B, C phases) of the power line have a display device with a capacitance sensor. Insulator, when the power line is electrified, the capacitive sensor can sense the voltage, and the voltage will be displayed on the electrified display. When the circuit breaker performs remote opening/closing operation through the external opening/closing contacts, the circuit breaker performs the opening/closing movement of the contacts, and the live display on the line can display the opening/closing results of the line. The present invention makes full use of this favorable condition, and realizes the determination of opening/closing time of the circuit breaker and the measurement of opening/closing non-synchronous time without adding facilities or adding any cost. The specific implementation is as follows:

As shown in Figure 2, the CG series capacitive sensor is used as the capacitive sensor in the embodiment. Under the action of the voltage on the power line, the sensor induces an alternating current of 40-50V. After the alternating current is connected to the charged display, the voltage is displayed. Due to the induction principle of the capacitive sensor, the voltage of the capacitive sensor directly reflects the voltage of the power line with almost no delay; the three-phase alternating current of the capacitive sensor is connected to the online monitoring device, and after the rectification and Filtering and photoelectric isolation first convert the three-phase AC voltage into a three-phase DC voltage, and then perform remote signal sampling of the three-phase voltage signal. When the voltage of the capacitive sensor is greater than 40 volts, the remote signal detected by the online monitoring device is 1, otherwise it is 0; The remote signaling signal (1 or 0) directly reflects the presence or absence of voltage on the power line, that is to say, it directly reflects the opening/closing state of the circuit breaker contacts.

When the circuit breaker performs the opening operation, the three-phase contacts of the circuit breaker perform separation movement, and the on-line monitoring device continuously detects the remote signal signals of the three sensor voltages of the capacitive sensor with a sampling period of 0.1 milliseconds, and records the remote signal from The displacement moments Taf, Tbf, and Tcf of 1 to 0, similarly, remote signaling has also undergone software debounce processing; that is to say, the moments when the three-phase contacts of the circuit breaker are separated are Taf, Tbf, and Tcf respectively; the separation of the contacts of the circuit breaker is completed The moment of , that is, the moment when the contact of the last phase is separated, is max(Taf, Tbf, Tcf).

When the circuit breaker is closing, the three-phase contacts of the circuit breaker will engage and the on-line monitoring device will continuously detect the remote signaling signals of the three sensor voltages of the capacitive sensor with a sampling period of 0.1 milliseconds, and record the remote signaling from The moment of shifting from 0 to 1 is Tah, Tbh, Tch. Similarly, the remote signal has also undergone software debounce processing; that is to say, the moment when the three-phase contacts of the circuit breaker are engaged are Tah, Tbh, and Tch respectively; when the contacts of the circuit breaker are engaged The moment of completion, ie the moment when the last phase contact engages, is max(Tah, Tbh, Tch).

Circuit breaker opening time T0: T0=max(Taf, Tbf, Tcf)-Tf;

Circuit breaker opening time T1: T1=max(Tah, Tbh, Tch)-Th;

The different opening time Ttq0 of the circuit breaker: Ttq0=max(Taf, Tbf, Tcf)-min(Taf, Tbf, Tcf);

Closing non-synchronous time Ttq1 of the circuit breaker: Ttq1=max(Tah, Tbh, Tch)-min(Tah, Tbh, Tch).

Claims (2)

1. The online monitoring method of the opening and closing time of the high-voltage circuit breaker. The online monitoring device conducts online monitoring of the circuit breaker opening time T0, closing time T1, opening different period time Ttq0, and closing different period time Ttq1, which includes Follow the steps below: (1) Sampling the remote signal of the voltage signal for the opening coil and closing coil of the circuit breaker, and recording the moment when the remote signal changes from scratch, which is the moment when the voltage signal is established in the opening coil and closing coil Time Tf, Th, and take Tf, Th as the initial moment of electrification of the opening coil and closing coil of the circuit breaker; (2) First convert the three-phase AC voltage of the capacitive sensor of the high-voltage live display device on the power line into a three-phase DC voltage, and then perform remote signal sampling of the three-phase voltage signal, and record the displacement of the three-phase remote signal from presence to non-existence Time and the moment of change from nothing to existence, the moment of change from existence to non-existence of the three-phase remote signal is the disappearance time Taf, Tbf, Tcf of the three-phase voltage signal, the moment of change from nothing to existence of the three-phase remote signal That is, the establishment time Tah, Tbh, Tch of the three-phase voltage signal, the disappearance time max(Taf, Tbf, Tcf) of the last phase voltage signal is regarded as the moment when the contact of the circuit breaker is separated, and the establishment time of the last phase voltage signal is Time max(Tah, Tbh, Tch) is used as the moment when the contacts of the circuit breaker are engaged; (3) Calculate the time difference between the start time Tf of the charging circuit breaker opening circuit and the time max(Taf, Tbf, Tcf) when the circuit breaker contacts are separated, that is, the opening time T0 of the circuit breaker: T0=max(Taf , Tbf, Tcf)-Tf; Calculate the time difference between the start time Th of the circuit breaker closing circuit charging and the time max(Tah, Tbh, Tch) of the circuit breaker contact completion time, that is, the closing time T1 of the circuit breaker: T1=max(Tah, Tbh, Tch)-Th; (4), calculate the maximum time difference of the three-phase voltage signal disappearance time Taf, Tbf, Tcf of the capacitive sensor, promptly obtain the different time Ttq0 of opening the gate of the circuit breaker: Ttq0=max(Taf, Tbf, Tcf)-min(Taf, Tbf, Tcf); Calculate the maximum time difference of the three-phase voltage signal establishment time Tah, Tbh, Tch of the capacitive sensor, that is, the different closing time Ttq1 of the circuit breaker: Ttq1=max(Tah, Tbh, Tch)-min(Tah , Tbh, Tch). 2. The online monitoring method of opening and closing time of a high-voltage circuit breaker according to claim 1, characterized in that the sampling frequency of voltage signal remote signal sampling is 10000 Hz, so that the monitoring time accuracy is 0.1 millisecond.

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